


Baishuu

by Marie9



Series: The Coins [2]
Category: Magic Kaito, Yu-Gi-Oh! Duel Monsters (Anime & Manga), 名探偵コナン | Detective Conan | Case Closed
Genre: Canon-Typical Violence, Conan Won't Let Them Close Enough To Check Though, Gen, He's Helping Though So Whatever, Mokuba And Noa Are Pretty Sure That 'Sleeping Kogoro' Is ACTUALLY Sleeping, That Kuroba Guy Seems To Know A Little Too Much About Security Systems, The Coins
Language: English
Status: In-Progress
Published: 2018-11-19
Updated: 2018-11-19
Packaged: 2019-08-26 04:01:00
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,561
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16674127
Author URL: https://archiveofourown.org/users/Marie9/pseuds/Marie9
Summary: Kaiba Mokuba has done his research along with his brother, Noa, and decided to hire the best detective in Japan, the famous 'Sleeping Kogoro,' after Seto starts behaving strangely during a business trip on top of seemingly vanishing out of the public eye suddenly.Unfortunately for the Kaibas, some of Kaiba Gozaburo's old business arrangements are now coming back to haunt them both literally AND metaphorically, and what starts out as a simple missing-persons case that Kogoro tries to convince them at first may not even really be a missing-persons case quickly becomes much more complex and dangerous than that.Luckily for Mokuba and Noa, when they hire 'Sleeping Kogoro' they also meet a very bright seven-year-old staying with him named Edogawa Conan and eventually a teenage friend of Conan's that seems to know a strange amount about security systems and electronics, Kuroba Kaito.Set in The Coins 'Verse.





	Baishuu

**Author's Note:**

> Been fleshing this one out for a while! With Sūtsu probably wrapping up in another chapter or two I wanted to really get started in on The Coins and well, this crossover has been in my head for -literally years-. I really hope everyone enjoys, and rest assured things are happening with my other stories as well!

The instant that he stepped in the office's door after school, Shinichi froze up and felt his heart sink down somewhere beneath the cheap carpet of the Mouri detective agency.

_I've got to find Ran and take her with me...run as far away as possible..._

He finally felt his mind trying to actually process the situation now, the meitantei managing to sputter out a few questions to himself in his mind as he studied the large guns the massive, black-suited men were holding. _How did they find me? What are they going to do to us?_ He shivered as he realized he already probably knew the answer to that question; they were very meticulous about not leaving any witnesses behind, after all. _I'm so sorry, Ran..._ His mind shifted into defensive mode, Shinichi reaching down for the belt that would release his hidden soccer ball. _I have to knock them out and find Ran and Kogoro...if they're still alive._

"Boss, we got another one. A little kid," called one of the men in the direction of the office where Kogoro normally received his clients, the large man barely fitting onto the cushion on the couch he was occupying. "You want we should let 'em in?"

"That's probably the boy we're taking care of, Edogawa Conan, coming home from school," came Ran's somewhat muffled, but very calm-sounding voice out of Kogoro's office. "Hi Conan-kun!"

After the huge wave of relief that washed over him at hearing Ran's voice passed, Shinichi began to realize that something was off here. If these guys _were_ the Black Organization, Ran and Kogoro would have both either been dead or close to it already, with him following closely behind the instant he'd stepped through the door. He studied the men more intently, taking in the clear earpieces they were wearing and their matching outfits. _Some kind of professional outfit? Hired bodyguards for someone, maybe?_ He felt his eyes narrow a bit.

"Make sure it's him, and then let him through," came a young male voice from the office that sounded far more mature than it should have to Shinichi's ear.

"Shut the door," growled one of the men at Shinichi, waving the end of his sub-machine gun towards the door to emphasize his point. "What's yer name, kid?" he continued gruffly after Shinichi closed the door.

Shinichi blinked before quickly answering "Edogawa Conan" on autopilot, realizing just how easy it had become for him to use the pseudonym _. And just who the heck are you guys...?_ He heard Kogoro's office door open before seeing Ran come out, who immediately ran over to Shinichi and knelt down to hug him with an exited smile.

"Guess who's here, Conan-kun!"

Before Ran could continue, however, Kogoro emerged, followed by two bodyguards that scanned the area before nodding to each other and waving back into the office. A boy of no more than twelve or thirteen stepped out of the office, his intelligent deep blue eyes carefully studying Shinichi behind wispy black bangs and his loose, thick waist-length black hair billowing slightly behind him as he walked. He stopped at the office's couches and gave them the same careful scrutiny he'd just given Shinichi. "Do people actually _sit_ on those things?" The voice was the same eerily mature one Shinichi had just heard in the office.

Kogoro looked insulted. "Hey, kid, I'll have you know that I've had those couches for years now, and-"

The boy's posture straightened visibly, his face showcasing clear irritation as he half-glared at Kogoro. "My name is _Kaiba Mokuba_ , not 'kid.' Mokuba-san will do." Mokuba's eyes were narrowed, and he said it in a firm tone that indicated he was very used to being in charge.

"Well, I'd like to take your case, but you really don't have any evidence that your brother is actually missing or in danger." Kogoro offered an apologetic shrug, and he continued in a conciliatory tone. "And really, he hasn't even been out of touch with you since he left- you said he's been calling you regularly, right? I'd bet that you have nothing to worry about."

Mokuba let out a snort. "Would I be wasting my time coming here if he _wasn't_ in danger, Mouri? And even if he's not actually in danger, _something's_ wrong." He shook his head firmly. "When nii-sama leaves me in charge of things, we have code words set up that we use during our calls." He crossed his arms defensively. "He hasn't been using them since he left." He sighed. "Look, I know nii-sama, alright? _Something_ is wrong, I just don't know what yet."

Shinichi found his curiosity piqued. "A code he hasn't used?" _Bright and childlike...bright and childlike..._

Mokuba turned to face Shinichi, nodding slightly. "Yeah. We always use it when nii-sama has to leave the country on business, so that I know any directions he's giving me are really coming from him." He looked up at Kogoro again, placing his hands on his hips. "And there's only two reasons it could be happening. Either the guy talking to me on the phone isn't really nii-sama, even though he looks and sounds just like him, or nii-sama's been kidnapped and he isn't using our code because he's being given orders by someone else to give to me."

Kogoro looked up at the ceiling for a couple moments and rubbed his chin thoughtfully. "Hmm. That sounds like something really could be going on." He sat down on the couch and pulled out a pencil and notepad from his breast pocket. "Has he said or done anything else anything unusual on the phone? Besides not using your code, that is."

"So you're _finally_ taking me seriously." Mokuba let out an irritated sigh and reluctantly sat down on the love seat across from the couch, his bodyguards standing at attention on either side of him. "No, he hasn't done or said anything else weird, but believe me, him not using our code is weird enough all by itself." There was a carefully controlled, but worried undertone to the response.

"When was the last time that you saw him _physically_? When you went to the airport to see him off, like you were telling us about in the office earlier?" Kogoro was continuing to write down notes.

Mokuba cleared his throat. "Nii-sama said he'd been approached about a contract to develop some 3-D games using the technology Kaiba Corp developed for our Duel Disks a while ago, but he didn't say much more than that. He took off in his private helicopter pretty early in the morning three days ago." He shifted his weight on the love seat, settling in a bit. "His helicopter got to the other airport OK, and in fact is still sitting in the plane storage there. But no one seems to have actually laid eyes on nii-sama since he checked his helicopter into storage and got taken off in a big, black stretch limo after he arrived in Kyoto from Domino City."

Shinichi's eyes narrowed reflexively as he took the information in, his detective instincts kicking into high gear. _Pretty strange. If he's been kidnapped, you'd think there would be some kind of ransom demand or something like that, with how much the guy must be worth. Well, assuming that Mokuba is talking about Kaiba_ Seto _, the CEO of Kaiba Corp, like I'm presuming he is..._ He dearly wished that he could knock Kogoro out and let 'Sleeping Kogoro' take over the questioning of Mokuba, but Shinichi knew it would be far too obvious and awkward to attempt. _I hope Mouri-ojisan at least thinks to ask him about who the older Kaiba was going to see..._

Kogoro flipped to a new page of his notepad. "And I take it you don't have any idea exactly what company that he was going to meet with? I'm sure you would have checked with them already if you did."

The shake of Mokuba's head in reply was accompanied by a dejected slump of his shoulders. "Nope. Which is another weird thing about this- nii-sama _always_ puts all of his appointments in his digital calendar, but nii-san and I couldn't find anything for the meeting he went to at all. The detectives we keep around can't seem to find anything either, even working around the clock." He looked up from the floor. "Which is why we've decided to hire you." Mokuba then pulled out a thick file folder, opening it to reveal several photocopied articles about 'Sleeping Kogoro's' exploits. "They say you're one of the best detectives in Japan, 'Sleeping Kogoro', and the checking into you we've had done seems to bear that claim out." His eyes flicked to Ran, then Shinichi, then Kogoro again. "I want you to find nii-sama."

"Of course," Kogoro began eagerly. "There is, however, the small matter of a retainer and expense money for research, Kaiba-san." He bowed his head slightly at Mokuba. "Nothing but a formality with you, I'm sure-"

Mokuba just leveled an annoyed glare at the detective before digging into his pocket and impatiently half-tossing a rumpled piece of paper roughly the size and shape of a check across the table. Kogoro picked it up off of the table and let out a small yell of excitement as he examined it.

"What are we waiting for? Let's go check that office and see what we can find!" Kogoro raced out the door as he tucked the check into his pocket.

Mokuba got up off of the love seat impassively. "Well, there _is_ something nii-san and I were going to need to check into at the office anyhow, so I suppose we should get going." He turned to Ran and Shinichi and cocked an eyebrow. "Is Mouri always like that?"

 _Only when a lot of money's involved,_ thought Shinichi with an inward laugh.

* * *

Over an hour later, Mokuba's stretch limo was heading into a forest with his bodyguards and Ran, Shinichi and Kogoro in tow. "So, uh, where are we going to right now, exactly?" Kogoro was looking out a heavily tinted window at rows of old, bare trees as the luxurious limousine they were in ground and occasionally bounced its way along a rather small and ill-maintained gravel road, its expensive engine seeming to groan in protest on occasion. "This sure isn't the way to Domino City."

"Nope, it's not" agreed Mokuba flatly as he reached into his pocket, producing a thick silver card that had the Kaiba Corp logo stamped onto it in silver overlay. "I'm stopping here to pick nii-san up. We'll go to nii-sama's office in Domino City once I'm done here and look around there with his help." He didn't seem inclined to say anything more than that.

Shinichi strained to look out the window as they drove, grabbing the dark brown wood-grained top of the inside of the limo's door and trying to pull himself up. He only managed to briefly catch a glimpse of a medium-sized grey steel sign with the Kaiba Corp logo emblazoned on it in black before he was pulled back down into his seat gently by his waist. _Just where_ is _he taking us to? We've been driving for well over an hour now, and we left the freeway a pretty long time ago..._

"Conan, don't move around like that. You should sit nicely when you're in a car, OK?" Ran followed the gentle scolding with him a warm smile as the car suddenly stopped in front of a massive pair of gates. Mokuba then held the card he'd pulled out earlier up to the car's window, and a deadpan female electronic voice issued from a nearby high-tech looking speaker box that was on Mokuba's side of the limo.

 _'Welcome' -_ there was a momentary pause before the voice continued in a slightly different tone- _'KAIBA,_ _MOKUBA.'_ The voice then returned to its initial tone. _'Please speak your pass phrase for voice verification and access.'_

Mokuba looked at everyone else in the car, including his bodyguards, with a light glare before very slowly opening his window. He then unbuckled his seat belt and stood up, leaning out the window slightly and cupping his hands around his mouth before he very quietly whispered something into the steel box.

_'Thank you KAIBA, MOKUBA. Voice scan and pass code authentication confirmed. Highest level security clearance granted.'_

The massive pair of wrought iron gates slowly swung open as Mokuba buckled himself back in before looking at Shinichi, Ran and Kogoro in turn as the limo drove down a now smooth, paved one-way road. "This will only take a little bit, so you guys can just wait in the car while I go get him." The tone of his voice was matter of fact, but also really didn't seem to be giving them a choice.

"So, uh, what _is_ this place exactly?" Kogoro noticed that it was no longer trees lining the roads. In fact, there were now several small white buildings scattered here and there along both sides of the road, men with black uniforms and guns standing watch at each and every building. The buildings all looked like large, white single-story warehouses with massive double doors leading into them.

"One of our storage and development facilities," explained Mokuba tersely as they came up to a large, windowless industrial building whose white walls were only broken up by a massive set of metal double doors. The limo stopped and Mokuba quickly undid his seat belt and hopped out, shutting the door behind him and walking over to a scanner similar to the one he'd used at the gate and placing his hand on it. After a few moments, the massive doors swung open and Mokuba entered the large building, all but two of his bodyguards falling in a sort of V formation around him. The two that had been left behind to watch Shinichi, Kogoro and Ran nodded to each other before settling their sunglass-covered gazes on the trio.

"I wonder what his brother's like..." muttered Ran under her breath as she looked out the window at the large building. A somewhat angry-sounding grunt from one of Mokuba's bodyguards cut her off from any further musings, at least verbalized ones.

Shinichi found himself wondering the exact same thing.  _She's right._   _I've never heard about there being a third Kaiba sibling, at least from what I've seen of them in the news. I guess we'll find out when he comes back out with him._  It therefore made Shinichi wonder more than a little when Mokuba got into the car by himself again after a few minutes- although now carrying a very small, somewhat thin well-locked light grey metal briefcase that was chained to his wrist.

"Hey, weren't you supposed to be picking your brother up? Where is he?" Kogoro gave Mokuba a puzzled look.

Mokuba held the case close to him, almost protectively, as he finished snapping his seat belt and settling in to his seat. He didn't respond to Kogoro, instead looking towards the front of the limo to give directions to the driver and snapping his fingers. "To headquarters in Domino City, and step on it." The limo began pulling away from the facility at very fast pace.

* * *

_Just what in the hell have you gotten me into_ this _time, Gozaburo?  
_

Kaiba Seto's eyes slowly scanned his prison yet again, his expression stony as he took in the bulletproof, deadbolted windows and thick steel door that couldn't be opened from the inside. Even dead twice over, Kaiba Gozaburo was _still_ managing to be a thorn in his side somehow. His captors didn't seem to want either money or his life- one of them had just let out a low, rather amused chuckle when he'd asked if those were what they were after. Whoever this black-jacketed group was, though, they sure weren't interested in the 3-D gaming technology that they'd supposedly set up the meeting with him to look at either. Of course, they'd made some very careless mistakes besides the kidnapping itself, the biggest one being deleting all records of the meeting from his calendar. That, Seto knew, along with him very deliberately not using their verbal code during calls would immediately have Mokuba and Noa both suspicious and trying to track him down- exactly what the CEO was planning and hoping for. At the thought of his brothers, he flipped open the locket around his neck that contained Mokuba's picture and studied it before studying Noa's picture that was secreted under Mokuba's. _I_ know _they'll figure out that something's wrong...the only question is how long it'll take._

"Tell me. Do you _ever_ smile, Kaiba-san?"

Seto felt his eyes narrow reflexively as he heard the silky, familiar voice of his female captor on the other side of the door along with jangling keys. He quickly shut his card-locket and got up from the seat he'd taken on his temporary bed, steeling himself mentally for another round with the slippery woman who had only given her name as Achika- an almost guaranteed alias. He had a moment of shock as an old man entered the room, slowly shuffling along with a cane and grabbing his hunched-over back with his free hand. Seto realized after a moment that this had to be another one of the woman's disguises and let out a light snort. "Nice costume." This was said in a flat, sarcastic tone.

"Why thank you, Kaiba-san. I'm quite fond of it." The discord between the elderly male face and the feminine voice coming out of it caused Seto to shake his head once. "I'm afraid I have to question you yet again before you can eat this evening," Vermouth continued, this time adopting a gravelly, well-worn old man's voice. "My superiors are getting rather impatient with you." She frowned and wagged an artificially crooked finger at Seto. "That could cause some real problems for young Mokuba-kun, you know." She felt a sudden pressure on her wrist, then realized that Seto had somehow managed to grab it in a split second. His eyes were filled with a cold, piercing hatred that actually managed to elicit a small shiver from her.

"If _any_ of you people hurt so much as a _single hair_ on Mokuba's head," Seto growled in a low, dangerous tone as he tightened his grip on Vermouth's wrist and glared daggers into her eyes, "you'll regret it." The hell if he was going to let them keep shooting arrows into his Achille's heel; Seto decided that it was time to nip any of those thoughts in the bud, and he very carefully refused to let anything slip about Noa's existence. He released her wrist, continuing to glare at the disguised woman as she rubbed her freed wrist briefly.

Vermouth recovered quickly, but realized for the first time that they might have grabbed a dragon by the tail. "Well, you won't need to worry about it if you'll simply cooperate with us, Kaiba-san."

"Then you people need to stop talking in all these damn riddles and just tell me what the _hell_ it is you want," Seto snapped, his voice full of irritation. "I've been here for three days and I still have no idea what you're after, except for the fact that Gozaburo was involved." He crossed his arms. "And like I've told you over and over, all of that research and development- and yes, I _do_ mean _all_ of it- got stopped after Kaiba Corp became a gaming company. There's nothing left of that man's."

Vermouth tilted her head. "Not even in some backup files or old records somewhere?"

Seto snorted and glared at Vermouth, venom and annoyance brimming in his reply. " _All._ Of. It. Is. Gone. I'm tired of repeating myself." Well, that _was_ a lie. It wasn't  _entirely_ gone, but he and Mokuba were deeply protective of Noa and like _hell_ he was going to reveal a damn thing about Noa to...whoever _these people_ were. When she gave him a disbelieving look, Seto elaborated, though his tone belied his impatience. "When I chose to turn Kaiba Corp into a gaming company, it was a complete and total change. Any workers that didn't agree with the change were let go, all weapons projects were halted and the records either destroyed or returned to whoever had hired Kaiba Corp for the development."

The only response from Vermouth at first was a sigh. "That may have proven to be a most unwise choice for you, Kaiba-san." She shook her head. "And I'm afraid that if your little brother goes poking around in your business much more, he may find himself in _way_ over his head."

"What do you mean by that?"

Vermouth smirked a bit at the question. "He seems to have gone off and hired 'Sleeping Kogoro' to try and track you down. That's what I mean, Kaiba-san." She turned and began walking out of the room. "For your sake, as well as your brother's, you should hope that he's not successful." She then heard the three taps on the door that indicated that Gin wanted an audience with her. "I'll bring you your dinner in a bit." She then closed and locked the door, quite a task with the arthritic hands she'd given herself, and followed Gin into another soundproof room in another part of the building, shutting the door behind them both.

"What do you think, Vermouth? Is he telling the truth?" Gin took a long drag on his cigarette before firmly flicking it over a nearby ashtray, the pair meeting quickly in a nearby room. " _He_ wants results, and soon."

"Of course he's telling the truth. He _has_ to be at this point after all of our tests," sighed Vermouth with a little shake of her head. "He doesn't seem to know anything about the test subject Kaiba Gozaburo mentioned to us, either. Kaiba-san seems to have been kept entirely in the dark about all of it." She shrugged and took a sip of water. "I suppose that really shouldn't surprise us, though, considering how young he would have been at the time we hired his father and all of the experimentation and development occurred."

"Well, he'd better come up with _something_ and soon. Some of us are beginning to get the feeling that he's deliberately delaying giving us the information."

Vermouth mulled over the best response for a few moments, carefully keeping her face expressionless. "We've been through it again and again with him, Gin, including using the truth serums multiple times. I'm convinced at this point that he truly has absolutely no idea what exactly we're after. So we need to try and get Mokuba-kun to do the digging for us, I suppose."

"Isn't _that_ what we've been making Kaiba _do_ for the past few days? Why the hell _else_ would we have let him contact his brother?" snorted Gin as he flicked his cigarette once or twice impatiently. "And _you're_ the one that thought it would be a good idea to just kidnap one and not both of them in the first place."

"We _had_ to change our plans when Kaiba-san showed up by himself. You know that as well I do." Vermouth waved her hand dismissively, suppressing a smirk as she did so. "But yes, we've been having him communicate with his brother, ordering him to have his brother look around for whatever he can find."

"Tell him he'd better get moving, then, because he's running out of time and so is his brother." Gin stood up and walked out of the room, pausing to crush his cigarette out on the floor with his heel before looking over his shoulder at Vermouth. "If there isn't some kind of change in the next forty-eight hours I've been authorized to get ugly. I suggest you emphasize that fact to our guest and explain exactly what that means." He then exited the room, deliberately slamming the door behind him.

 _He was in an even worse mood than usual,_ reflected Vermouth before she herself stood up and walked towards the back of the building, once again in front of the fully locked and soundproofed room where Kaiba Seto was being held. She pulled the key to the room out of her purse and opened the door, giving the CEO a few moments with the door still shut to compose himself before she entered the room. "We meet again, Kaiba-san. I'm afraid I have bad news for you."

Seto gave her the cold, icy glare Vermouth had become accustomed to as he crossed his arms, keeping his voice even. "Nothing's changed. I still have _no idea_ exactly what in the hell it is that you people _want_ , Achika."

"But we've already told you, Kaiba-san. We're interested in some old projects of your father's. We just need access to his old research, that's all."

The CEO's eyes narrowed as he shook his head. "Then we'll just keep going around in circles and wasting our time, won't we? I already told you, _all of that_ was destroyed when I took over Kaiba Corp, and I don't like repeating myself."

"The people I report to are getting angry, Kaiba-san. And they don't believe you, either. I _truly_ believe you, but unfortunately my opinion isn't the only one that counts." She sighed and wagged her finger. "You'll be dealing with someone much less polite than me if we don't start seeing results soon."

Seto merely shrugged and narrowed his eyes a little. "And that's my problem _how_ , exactly? You people waited until that man's been dead for _years_ to try and get whatever it is you're after." He allowed himself a smirk. "In addition to not doing your homework about the company's recent history."

Even though he was absolutely right, Vermouth wondered just how much she should reveal. "Cooperate with us, Kaiba-san. The sooner you do, the sooner we'll be out of your business and your life."

"How am I supposed to 'cooperate' when I have _no idea_ what you're looking for besides it being something that Gozaburo was involved in?" He let out a somewhat irritated snort. "That man had his fingers in a thousand pies all the time."

"Have Mokuba go through old records, as we've been asking you to do. That's how." She held out an untraceable cellphone to Seto. "Then we can release you and this will all be over."

Seto looked at the phone before returning his glare to Vermouth. "And how do I know I won't wind up dead once you people have whatever it is you're after?" _And that you won't kill Mokuba and Noa,_ though he sure as hell wasn't going to voice that aloud.

Vermouth offered Seto what seemed to be, for her, a genuine smile, though Seto still didn't like how unreadable the woman was. "We _really_ don't like killing anyone unless it's absolutely needed, Kaiba-san. It generally brings...unwanted attention, shall we say."

 _I guess we have to break this stalemate at some point._ Seto took the phone and dialed Mokuba's number, letting out a relieved sigh when his brother answered. "I'm calling to check up on things," he stated without preamble after Mokuba finished answering, finally using one of their many codes they had set up.


End file.
